>> with the calendar it is possible to tell exactly what the phase of the moon will be on a particular day 2,000 years from now or 2,000 years before now. >> reporter: they had a variety of calendars that ran in cycle of the sun, the moon and visible planets. >> why was the solstice important? >> it was very important because they kept a record. they can now know that the rainy season is going to begin and for the construction of the building they only use great amount of labor of many tools, just hammer and chisel. >> there are sweat baths there. there is an observatory. it was a private space. for all indications was a living space for the king. the temple was a great king that